This invention relates to endodontia which is specifically the practice of emptying dental radicular canals using instruments, manual or actuated by mechanical means, commonly known as "endodontic drills". The subject of the invention is a canal instrument created to contemporaneously:
eliminate cavity interference; PA1 widen the canal openings; PA1 straighten the curved areas of the canal through gradually extended flared reaming, starting from the external occlusion orifice of the "operation canal" and continuing to the third apical region. PA1 (1) a step; PA1 (2) a false path; PA1 (3) apical flaring (see FIGS. 6 and 7).
In order to clarify the original aspects of the invention in question, it should be understood that:
(1) the term "operation canal" is meant to imply the sum of the anatomic radicular canal and of the artificial canal which makes it possible to penetrate the occlusion surface in the former. This is achieved artificially, through reaming, in the roof of the pulp chamber composed of enamel covered dentine (see FIGS. 1 and 2).
(2) "interference" means all anatomic formations characteristic of the walls of the pulp chamber and of the radicular canals which, in the form of crowns, burr or curves, impede the insertion and rectilineal progress of an instrument in the radicular canal, consequently conditioning the work of the reaming surfaces, the stem and the tip of the canal instrument (see FIGS. 1 and 2).
(3) in the majority of cases, the radicular canals have curves which affect them over their full length (as is the case in respect of the mesial canals of the bottom molars (FIG. 3), the vestibular canals of the top molars (FIG. 2) and frequently of the third apical region.
Consequently, the opening of the canals often does not coincide with the axis of the curved section of the canal and, furthermore, is covered with burr formed by the cavity walls at the point where these continue with the floor of the pulp chamber, and thus suitable instruments such as, for example, Batt burrs (see FIG. 4) have to be used to remove at least the upper half of the triangle marked (a) shown in FIGS. 2 and 3 given as examples.